Cast Study – Urban Hospital Heating Water
     


By Jenny Conte

CLIENT: Large Highrise Urban Hospital with Hot Water for Heating

CHALLENGE: Reduce cost of how water heating

BACKGROUND: The hospitals heating water temperature was 180F year-round. So, on 90F summer days the heating water was maintained at 180F. The water was heated using steam to hot water converters, heat exchangers, located in the basement of the hospital.

PRELIMINARY ANALYSIS: The hot water was needed to heat several cardio vascular operating rooms (CVOR). The CVORs had to have the capability of being warmed up to 85F within thirty minutes which required the 180F heating water. So, and almost 1,000,000 square foot hospital had its heating water heated to 180F year-round for just two rooms.

ACCLAIM’S EXPERTISE AT WORK: Testing was performed to determine if water cooler than 180F would meet the warm up requirements for the rooms. The heating water temperature was decreased in 5F increments and it was determined that heating water at 155F would meet the requirements. The hospitals heating water temperature was reduced to 155F. While a reducing the heating water temperature to 155F was a good thing the 155F was still to hot for most of the year. It was observed that there was 15# steam available in the vicinity of the air handler that serves the CVORs. A small skid steam to hot water converter was installed to only feed hot water to the CVOR air handler. This steam to hot water converter was sized to provide 180F heating water to the CVOR air handler by warming 125F building water. The building heating water temperature was lowered to between 125F and 135F again reducing steam consumption.

RESULTS: The 25% reduction is steam consumption resulted in an annual savings of $200,000.

THE “TAKE AWAY”: Always try to fit an energy supply to the needs of a whole facility and accommodate specialty needs with auxiliary systems.